Mask-washing machine



H. SZCZEPANSKI MASK-WASHING MACHINE Jan. 15, 1957 Filed NOV. 19, 1954 /nven/0r y Szczegansk/ y I X M Af/Omqy Harr Ullll llillulllll ri rii- United States Patent MASK-WASHING MACHINE Harry Szczepanski, Grand Rapids, Mich. Application November-'19, 1954, Serial No. 470,036

2 Claims. (Cl. 134-200) This invention has been developed primarily for the washing of paint from masks used in the process of spray painting to block off areas on the sprayed objects where paint is not desired. After a period of use, a sufiicient quantity of paint accumulates on the masks to interfere with their ability to establish a clean unobstructed outline of the painted surface. It then becomes necessary to remove the paint from the masks through the use of a solvent so that the masks can again be relied upon to provide the desired line of demarcation between painted and unpainted areas. The application of the solventto the masks may be through the process of immersion, or through the projection of the solvent at the masks with a stream or spray. It is with the latter type of cleaning device that this invention is preferably associated.

In general terms, the basic components of a convenient form of a washing unit of this type include a pressure tank with a spray chamber disposed directly above it. A drainage conduit communicates between the bottom of the tank and the pressure container, with a check valve restricting flow to the direction from the spray chamber to the pressure container. The pressure container is normally substantially full of solvent, and an air pressure line under the control of a manually-operated valve communicates with the pressure chamber. Actuation of the control valves admits a charge of air pressure to the container to induce flow from the container through a series of spray nozzles disposed within the spray chamber. Suitable racks are provided in the spray chamber for mounting masks to be cleaned, and the solvent from the spray falls from the masks downward to the bottom of the chamber Where it accumulates until the pressure in the lower container has been dissipated. The check valve controlling the drain from chamber into the pressure tank then opens, permitting the return of the solvent to the tank for another cleaning operation. A device of this general type is shown and described in my application for patent Serial Number 299,540, filed on July 18, 1952.

This invention provides for a mounting of racks to which masks are attached for the cleaning operation, with arrangement being made for at least partial elevation of the racks out of the spraying chamber with the opening of the cover of the machine. Arrangement is also made for the mounting of the spray racks at selected distances from the spray units so that the desired relationship can be established to accommodate particular cases.

There are several features of this invention that will be analyzed in detail through a discussion of the particular embodiments illustrated in the accompanying drawings. Referring to the drawings:

Figure 1 presents a sectional elevation of a modified form of a machine embodying this invention.

Figure 2 presents an enlarged detail of the workmounting racks and the supporting-brackets thereof.

Figure 3 shows an enlarged view of the drainage conduit communication between the spray chamber and the pressure tank of the device illustrated in Figure 1.

Referring to Figure 1, a housing 56 encloses a pressure ice 59. The conduit communicating between these areas is best illustrated in Figure 3, and includes the pipe 60 positioned with its opening at the upper end 61 slightly above the floor 58 of the spray chamber 59. Preferably, a flange 62 is secured to the pipe 60 by welding orbrazing, with the assembly secured with respect to the floor of the spray chamber by bolts as indicated by 63 and 64 in Figure 3.

The pipe 60 leads downwardly into the check valve generally indicated at 65, which is mounted within the pressure tank 57. This positioning of the check valve 65 eliminates the necessity for at least one pipe connection, since the discharge moving downward through the pipe 60 is dumped directly into the tank through the lower opening at the end 66, with some of the discharge possibly emerging through opening at the side 67. The absence of a connecting pipe entering at the opening in the side 67 permits the balance arm assembly 68 to protrude for assembly, movement, and adjustment. This arm assembly is secured to the fiat valve member 69 so that the formation of forces about the pivot pin 70 results in equilibrium of the valve adjacent the closed position illustrated in Figure 3.

The mounting of the check valve 65 within the pressure container 57 may conveniently be provided through the use of a fitting 71 welded to the structure of the container, and threaded interiorly to accommodate the exteriorlythreaded section of pipe 72. A protrusion of the pipe 72 below the fitting 71 engages the check valve 65, while the upper end thereof receives the nut 73. To allow for tmanufactun'ng variation between the position of the floor 58 and the pressure tank structure the pipe 60 should be slideable with respect to the structure mounted on the pressure tank until the lock nut 73 is tightened. This characteristic is provided by standard plumbing fixtures which need not be analyzed in detail here.

Referring to Figures 1 and 2, an arrangement is illustrated in which the opening of the cover 74 results in the partial elevation of the work-support rack 75 out of the spray chamber 59 for easier access to the pieces mounted for cleaning. The wire grill-work 75 is provided with laterally-projecting extensions 76 and 77 which are received in the hole 78 of the brackets 79 and 80 mounted on the cover 74. Each of the brackets 79 and 80 are provided with a similarly-located set of holes 78, with each set of opposite holes receiving the projections 76 and 77 with the rack 75 at a particular desired distance from the spray units. The brackets 79 and 80 may be deflected laterally to the position shown in dotted lines to permit the withdrawal of the projections 76 and 77, and movement of the rack to a different set of opposite holes 78.

This change of position of the rack 75 alters the relationship of any articles which may be placed upon it with respect to the spray nozzles 80 and 81. Varying spray conditions will necessitate relocation of the rack 75, possibly coupled with a varying adjustment of the spray pattern to achieve the desired results. The nozzles 80 and 81 are each supplied with liquid from the conduit 82, which is in turn controlled by a valve unit 83. A filter unit 84 is interposed in the line 85 which traverses the floor 58 of the spray chamber 59, and connects with the pressure tank 57. The flow of solvent from the pressure tank 57 upwardly through the line 85 and the conduit 82 Patented Jan. 15, 1957 1; In a processing machine having a work chamber 1 provided with spraying means: a hinged cover for said chamber; spaced opposite bracket means mounted on said'cover and having a resilient portion provided with sets of apertures and capable of deflection to increase the distance between said bracket means; and work-receiving rack means suspended from said bracket means within said chamber, said rack means having portions engaging said apertures whereby said rack means are pivotally suspended on an axis parallel to the hinge axis of said cover, said rack means being positionable at selected distances from said spray means corresponding to thepositions of said sets of apertures.

2. In a processing machine having a Work chamber provided with spraying means: a cover for said chamber;

spaced opposite bracket means mounted on said cover and having a resilient portion provided with sets of apertures and capable of deflection to increase the distance between said bracket means; and work-receiving rack means suspended from said bracket means within said chamber, said rack means having portions engaging said apertures, said rack means being positionable at selected distances from said spray means corresponding to the positions of said sets of apertures.

References Cited in the file of this patent UNITED STATES PATENTS 396,765 Power Jan. 29, 1889 1,836,373 Kadesch Dec. 15, 1931 2,554,389 Stevens May 22, 1951 2,570,021 Beach Oct. 2, 1951 2,618,281 Hiort at Ornas Nov. 18, 1952 2,703,093 Boyen Mar. 1, 1955 

